trail - evidence pointing to a possible solution; the police are following a promising lead; the trail led straight to the perpetrator track, lead evidence, grounds - your basis for belief or disbelief; knowledge on which to base belief; the evidence that smoking causes lung cancer is very compelling
The process by which the oceanic crust is pulled under the continental crust is called subduction and the zone at which this occurs at the plate boundaries is called the subduction zone. At the subduction zone where the oceanic crust sinks beneath the continental crust a deep oceanic trench or valley is created.
Convergent boundaries are plate boundaries formed when two tectonic plates crush together. The denser of the two plates goes under the other! For example, if two oceanic plates (which are tectonic plates found in the ocean) collide, the denser of the two plates goes under the other and forms an oceanic trench. If an oceanic plate and a continental plate collide (a continental plate is a tectonic plate that holds land/continents), the oceanic plate will go under the continental plate and goes into the mantle. If two continental plates collide, the crust thickens and is forced to create landforms such as mountains.